MedicalResearch.com Interview with:
Stavros V. Konstantinides, MD, PhD, FESC, FRCP(Glasg)
Professor, Clinical Trials, and Medical Director
Center for Thrombosis and Hemostasis (CTH)
Johannes Gutenberg University Mainz
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Acute pulmonary embolism (PE) is the third most frequent acute cardiovascular syndrome. It encompasses a wide spectrum of clinical symptoms and severity, ranging from massive, immediately life-threatening PE with hemodynamic collapse to the low-risk, stable patient with very few symptoms. These latter patients with acute low-risk PE may qualify for early discharge from hospital (e.g., within 48 hours) and continuation of treatment at home. This is a very promising strategy, because it may not only increase patient satisfaction and quality of life, but also help to reduce hospital-related complications and costs. However, it needed to be clearly determined, and tested in a prospective management trial, who are the appropriate candidates for an effective and safe home treatment approach. To this date, trials suggesting favorable clinical outcomes with home treatment of PE are small and date back to the era of vitamin K antagonists. Direct oral anticoagulants permitting a single drug treatment of PE are more promising in this regard, as they may make an early transition from hospital to ambulatory care both safer and more convenient.
The international Home Treatment of Pulmonary Embolism (HoT-PE) phase 4 management trial tested the efficacy and safety of early discharge and ambulatory anticoagulation treatment with the direct factor Xa inhibitor rivaroxaban in patients with acute low-risk PE. Patients were identified on the basis of
- clinical criteria or PE severity, comorbidity, and contraindications; and
- the absence of right heart failure or intracardiac thrombi on cardiac imaging. Early termination of the study was possible following the prespecified interim analysis, which was performed after recruitment and 3-month evaluation of 525 patients (50% of the planned trial population). At the interim analysis, the primary efficacy outcome of symptomatic recurrent venous thromboembolism or PE-related death occurred in only 3 (0.6%) patients (compared to an estimated 1.7% rate based on historical data). This rate was sufficiently low to reject the primary hypothesis as predefined in the statistical analysis plan. None of the recurrent events was nonfatal.Major bleeding occurred in 6 (1.2%) patients of the safety population. The study could therefore be terminated early for efficacy.